Among detection devices that detect light emitted onto a detection target object, for example, there are items that perform inspection of the detection target object by capturing an image of the detection target object based on detected light and using image data formed from the captured image. Technology disclosed in patent literature 1 is for performing inspection of a detection target object by imaging the detection target object from two directions using two imaging devices and performing inspection based on image data formed from the images captured from the two directions. Also, because the efficiency is poor when imaging the detection target object from two directions using two imaging devices, technology disclosed in patent literature 2 is for imaging a detection target object from two directions using only one imaging device.    Patent Literature 1: JP-A-2006-41158    Patent Literature 2: JP-A-2012-4306